When: Periodical cicadas (Magicicada septendecim) are unique to eastern North America and are found nowhere else in the world. The emergence of periodical cicadas often begins in mid- to late May when soil temperatures are approximately 64 degrees F. The start of the mass emergence of periodical cicadas is usually preceded by a warm rainfall event.

Description: Adults are about 1½ inches long and have eyes and wing veins that are reddish-orange. They are smaller than their cousins, the dog-day cicadas. Dog-day cicadas, Tibicen spp., are mostly large, blackish insects usually with greenish wing veins and appear every year from mid-July through mid-September.

Reproduction: About 10 days after emergence, females will mate and begin depositing eggs in twigs and branches of nearly 80 different preferred species of trees and woody shrubs. They usually do not deposit eggs in coniferous trees. Generally, the female will deposit 400 to 600 eggs in the twigs of their preferred species. Using the blades of a sawlike egg-laying device at the end of the abdomen, females puncture the bark of a twig and make a pocket in the wood. Females may deposit 24 to 28 eggs in two rows in one of these pockets. They then move forward, cut another pocket, and lay more eggs. The pockets are placed close together in a straight row, sometimes forming a continuous slit for 2 to 3 inches. Adults live for approximately three to four weeks above ground. Most are usually gone by the beginning of July.

Nymphs: Hatching occurs six to seven weeks after egg-laying, and the white, antlike nymphs work their way out of the slits and drop to the ground, where they enter the soil. Here they insert their piercing-sucking mouthparts and draw plant fluid from roots of plants for the next 17 years.

Threats: Adults do not feed on leaves. If they feed at all, it is by sucking plant fluid from tender young twigs. The most noticeable damage done by periodical cicadas is from egg-laying. Twigs slit by the female's ovipositor will frequently have leaves that wilt and die. Many of the damaged twigs will break off and drop to the ground. Fruit and nut orchards can suffer heavy pruning losses from high populations of these insects. The effect of root feeding by the nymph is considered inconsequential to most trees.

Benefits: The mass emergence of nymphs provides easy pickings for numerous mammals including black bears, raccoons, skunks and shrews; birds such as crows, blue jays, wild turkey, hawks, flycatchers and bluebirds. Land-dwelling reptiles and amphibians enjoy the feast including eastern garter snakes, smooth green snakes, wood and box turtles, wood frogs, green frogs and toads. The flying adults are consumed by practically every species of birds as well as mammals including bats. Any nymph or adult that falls into a stream, pond or lake is quickly consumed by fish such as bluegill, largemouth bass and smallmouth bass and perch.